1. Technical Field
The present invention relates to a common mode filter.
2. Background Art
High-speed digital interfaces, such as USB, require a part that addresses noise. One of such parts that removes common mode noise selectively is a common mode filter.
Common mode noise can occur when impedance fails to be parallel in the wiring system. The common mode noise can occur more often for higher frequency. Since the common mode noise can be also transferred to, for example, the surface of the earth and bounced back with a big loop, the common mode noise causes various kinds of noise troubles in far-away electronic devices.
The common mode filter can allow a differential mode signal to bypass while selectively removing the common mode noise. In the common mode filter, magnetic flux is canceled out by the differential mode signal, causing no inductance to occur and allowing the differential mode signal to bypass. On the other hand, magnetic flux is augmented by the common mode noise, increasing the inductance and allowing the noise to be removed.
The related art of the present invention is disclosed in Korea Patent Publication No. 2011-0129844 (COMMON MODE NOISE FILTER; laid open on Dec. 6, 2011).